Cost and capacity analysis for representative EU energy grids depending on decarbonisation scenarios

This work studies the transformation of energy grids of the European Union (EU) in the frame of the energy transition. Three energy grid types are considered namely the electricity, thermal and gas grids.

Regarding electricity grids, we investigate the required reinforcements of the low-voltage networks (e.g. replacing the distribution transformer by one of higher nominal power, replacing cables by cables of larger cross-section) in order to integrate residential low-carbon technologies such as heat pumps, photovoltaic systems and electric vehicles. To do so, we develop a methodology for the quantification of EU low-voltage grid reinforcement costs following residential low-carbon technologies integration. This methodology uses urbanisation data to determine the share of dwellings in rural and urban areas in EU28 countries (EU27 + United Kingdom). It is also based on a model that quantifies the grid reinforcement cost as a function of the low-carbon technologies integration scenario for representative rural and urban grids. This model is composed of three sub-models, namely the dwelling, grid and economic models. We also collected data from 24 open access grids (i.e. grids of which the specifications are freely accessible online) and 23 scientific articles and reports to determine the parameter values of the grid and economic models for EU28 countries. Finally, we provide example applications that illustrate the methodology by computing the grid reinforcement costs from heat pumps and photovoltaic systems integration in Belgium and Italy. Results indicate that, in the largest majority of cases, both for Belgian and Italian grids, the reinforcement cost per dwelling remains below 350 € per dwelling (total cost for the whole lifespan of 33 years). The only case where more significant reinforcement costs occurred (> 350 €/dwelling and up to 1150 €/dwelling) is for the Belgian rural grid with heat pump integration rates larger than 40%.

When it comes to thermal grids, we investigate the deployment of district heating, a heat supply technology that by its fundamental idea incorporates energy efficiency and thus can trigger important greenhouse gas emissions reduction. For this purpose, we proposed an approach to map the cost of thermal grids deployment per heat demand unit in the EU. This approach is based on the concept of representative thermal grids which corresponds to a principal equation that defines the distribution capital costs as the ratio of empirically derived specific investments costs and the linear heat density. In the sEEnergies project, this concept is expanded to comprise better cost models based on actual district heating network layouts at the spatial resolution of 1 hectare. While in the Heat Roadmap Europe project, the variables were generated only for the 14 EU Member States with largest annual volumes of building heat demands, the present approach covers all EU27 Member States plus United Kingdom. In this deliverable, we focus on the current year, while the deliverable 4.5 focuses on the future years.

Regarding gas grids, we present the key technical and economic characteristics of the existing gas grids and storages in the EU28 countries. We focus not only on infrastructure for natural gas but also for biogas, biomethane, syngas and hydrogen, which could play an important role in the decrease of greenhouse gas emissions. This techno-economic review provides important information to assess the cost of retrofitting and developing gas grids depending on the decarbonisation scenarios.